He also came very close to one fellow abuser, called Phillipa.75 - who it later emerged was a man.

They would live out sick fantasises online over the nine month period before his arrest.

In them Whitlock and Phillipa played adults with young daughters called Pippa and Naomi respectively, who they would abuse in sick roleplays.

Mr Brown added: “(They discussed) the possibility of acquiring a crated child and abusing it, killing it and disposing of the body.

“There are graphic representations of the manner of the abuse and the manner the child would have been killed.”

On his arrest Whitlock claimed a break in at his house may have caused the files to be on his computer.

He later changed this and pleaded guilty to one charge of possessing and one charge of making indecent images of children.

He also admitted one charge of distributing an indecent image of a child and one charge of publishing obscene material which related to the sick child murder fantasy.

Whitlock, of no fixed address, was jailed for 16 months for all four offences.

Jailing him, Judge Jonathan Howarth said: “Over a period of nine months you were in contact with like-minded individuals where you discussed fantasises in relation to you in particular you engaged in discussions which are frankly horrifying.

“You were engaging in roleplay or scenarios that would sicken any normal minded person.

“It was lurid and detailed. It shows that you clearly have a precondition for children in sexual offences.”

Whitlock must also signed the sex offenders’ register for 10 years after his release and be subject to a Sexual Harm Prevention Order for 12 years.